Heavy use of alcohol can lead to thiamine deficiency and Wernicke encephalopathy.
Reduced levels of thiamine in the blood and cerebrospinal fluid have been reported in individuals taking phenytoin (Dilantin®) for...Full Answer

St. John's wort interferes with the way the body processes many drugs using the liver's "cytochrome P450" enzyme system. As a result, the levels of these drugs may be increased in the blood in the short-term (causing increased effects or potentially serious adverse reactions)...Full Answer

Extracts of Hypericum perforatum L. (St. John's wort) have been recommended traditionally for a wide range of medical conditions. The most common modern-day use of St. John's wort is the treatment of depression. Numerous studies report St. John's wort to be...Full Answer